Voters in the state of Maine have voted to reject a law legalising same sex marriages. Clearly, a major setback for those supporting marriage equality. Every time such a proposal has been put before the voters in a referendum, it has been rejected.

However, the winners should take little comfort here, as they are surely looking future defeat in the face. Consider this graph on public attitudes to same sex marriage in the US:

Support for Legal Recognition of Same-Sex Marriage, 1988-2009Source for data: pollingreport.com

It shows that nationwide support for same sex marriage is currently at just over 40 per cent in the US. Not enough, not nearly enough, to overcome opposition. But when one considers that twenty years ago, support was barely scraping above 10 per cent, and the prospects look a little different (the article from which I took the above graph explains the apparently anomalous drop in support in 2003). The fact that the votes in places like Maine and California were so close makes a future vote in favour of gay marriage more a matter of when rather than if.

Supporters of gay marriage in the US will be feeling depressed this morning. But whether it takes ten, twenty or fifty years, they seem destined to find themselves eventually on the winning side of the public opinion battle.